Helical ordering of envelope-associated proteins and glycoproteins in respiratory syncytial virus.

Human respiratory syncytial virus (RSV) causes severe respiratory illness in children and the elderly. Here, using cryogenic electron microscopy and tomography combined with computational image analysis and three-dimensional reconstruction, we show that there is extensive helical ordering of the envelope-associated proteins and glycoproteins of RSV filamentous virions. We calculated a 16 Å resolution sub-tomogram average of the matrix protein (M) layer that forms an endoskeleton below the viral envelope. These data define a helical lattice of M-dimers, showing how M is oriented relative to the viral envelope. Glycoproteins that stud the viral envelope were also found to be helically ordered, a property that was coordinated by the M-layer. Furthermore, envelope glycoproteins clustered in pairs, a feature that may have implications for the conformation of fusion (F) glycoprotein epitopes that are the principal target for vaccine and monoclonal antibody development. We also report the presence, in authentic virus infections, of N-RNA rings packaged within RSV virions. These data provide molecular insight into the organisation of the virion and the mechanism of its assembly.

The Plasmodium NOT1-G paralogue is an essential regulator of sexual stage maturation and parasite transmission.

Productive transmission of malaria parasites hinges upon the execution of key transcriptional and posttranscriptional regulatory events. While much is now known about how specific transcription factors activate or repress sexual commitment programs, far less is known about the production of a preferred mRNA homeostasis following commitment and through the host-to-vector transmission event. Here, we show that in Plasmodium parasites, the NOT1 scaffold protein of the CAF1/CCR4/Not complex is duplicated, and one paralogue is dedicated for essential transmission functions. Moreover, this NOT1-G paralogue is central to the sex-specific functions previously associated with its interacting partners, as deletion of not1-g in Plasmodium yoelii leads to a comparable or complete arrest phenotype for both male and female parasites. We show that, consistent with its role in other eukaryotes, PyNOT1-G localizes to cytosolic puncta throughout much of the Plasmodium life cycle. PyNOT1-G is essential to both the complete maturation of male gametes and to the continued development of the fertilized zygote originating from female parasites. Comparative transcriptomics of wild-type and pynot1-g- parasites shows that loss of PyNOT1-G leads to transcript dysregulation preceding and during gametocytogenesis and shows that PyNOT1-G acts to preserve mRNAs that are critical to sexual and early mosquito stage development. Finally, we demonstrate that the tristetraprolin (TTP)-binding domain, which acts as the typical organization platform for RNA decay (TTP) and RNA preservation (ELAV/HuR) factors is dispensable for PyNOT1-G's essential blood stage functions but impacts host-to-vector transmission. Together, we conclude that a NOT1-G paralogue in Plasmodium fulfills the complex transmission requirements of both male and female parasites.

Non-invasive surveillance of Plasmodium infection by real-time PCR analysis of ethanol preserved faeces from Ugandan school children with intestinal schistosomiasis.

BACKGROUND: As part of ongoing co-surveillance of intestinal schistosomiasis and malaria in Ugandan school children, a non-invasive detection method for amplification of Plasmodium DNA using real-time (rt)PCR analysis of ethanol preserved faeces (EPF) was assessed. For diagnostic tabulations, results were compared to rtPCR analysis of dried blood spots (DBS) and field-based point-of-care (POC) rapid diagnostic tests (RDTs). METHODS: A total of 247 school children from 5 primary schools along the shoreline of Lake Albert were examined with matched EPF and DBS obtained. Mean prevalence and prevalence by school was calculated by detection of Plasmodium DNA by rtPCR using a 18S rDNA Taqman® probe. Diagnostic sensitivity, specificity, positive and negative predictive values were tabulated and compared against RDTs. RESULTS: By rtPCR of EPF and DBS, 158 (63.9%; 95% CI 57.8-69.7) and 198 (80.1%, 95% CI 74.7-84.6) children were positive for Plasmodium spp. By RDT, 138 (55.8%; 95% CI 49.6-61.9) and 45 (18.2%; 95% CI 13.9-23.5) children were positive for Plasmodium falciparum, and with non-P. falciparum co-infections, respectively. Using RDT results as a convenient field-based reference, the sensitivity of rtPCR of EPF and DBS was 73.1% (95% CI 65.2-79.8) and 94.2% (95% CI 88.9-97.0) while specificity was 47.7% (95% CI 38.5-57.0) and 37.6% (95% CI 29.0-46.9), respectively. With one exception, school prevalence estimated by analysis of EPF was higher than that by RDT. Positive and negative predictive values were compared and discussed. CONCLUSIONS: In this high transmission setting, EPF sampling with rtPCR analysis has satisfactory diagnostic performance in estimation of mean prevalence and prevalence by school upon direct comparison with POC-RDTs. Although analysis of EPF was judged inferior to that of DBS, it permits an alternative non-invasive sampling regime that could be implemented alongside general monitoring and surveillance for other faecal parasites. EPF analysis may also have future value in passive surveillance of low transmission settings.

How to use Twitter at a Scientific Conference.

In the past decade, social media platforms have been recognized as an important tool in the dissemination of science among the research community and as an interface between scientists and the general public. Publishing companies that specialize in scientific research now pay attention to alternative metrics ("altmetrics") and provide comprehensive guides about social media management to editors. Twitter has emerged as a leader among social media platforms in the dissemination of science. This Perspective will assert the merits of using Twitter to expand the reach of scientific conferences while providing guidance on how to disseminate conference findings in real-time, called "live-tweeting," without compromising scientific integrity.

Building Parasitology Communities to Promote Gender Equality.

In an ideal world, there are equal opportunities for women to enter and progress in all scientific disciplines without bias or prejudice. Here, we share our experiences in building communities of women parasitology and offer easy-to-implement guidelines for scientists and institutions to overcome unconscious bias and create environments with better gender equality and diversity.

Recent advances in malaria genomics and epigenomics.

Malaria continues to impose a significant disease burden on low- and middle-income countries in the tropics. However, revolutionary progress over the last 3 years in nucleic acid sequencing, reverse genetics, and post-genome analyses has generated step changes in our understanding of malaria parasite (Plasmodium spp.) biology and its interactions with its host and vector. Driven by the availability of vast amounts of genome sequence data from Plasmodium species strains, relevant human populations of different ethnicities, and mosquito vectors, researchers can consider any biological component of the malarial process in isolation or in the interactive setting that is infection. In particular, considerable progress has been made in the area of population genomics, with Plasmodium falciparum serving as a highly relevant model. Such studies have demonstrated that genome evolution under strong selective pressure can be detected. These data, combined with reverse genetics, have enabled the identification of the region of the P. falciparum genome that is under selective pressure and the confirmation of the functionality of the mutations in the kelch13 gene that accompany resistance to the major frontline antimalarial, artemisinin. Furthermore, the central role of epigenetic regulation of gene expression and antigenic variation and developmental fate in P. falciparum is becoming ever clearer. This review summarizes recent exciting discoveries that genome technologies have enabled in malaria research and highlights some of their applications to healthcare. The knowledge gained will help to develop surveillance approaches for the emergence or spread of drug resistance and to identify new targets for the development of antimalarial drugs and perhaps vaccines.